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991.
992.
993.
994.
Jorge Almeida 《Semigroup Forum》1993,46(1):90-97
Communicated by G. Lallement 相似文献
995.
Summary In this note we use the Hopf map π: S3 → S2 to construct an interesting family of Riemannian metrics hfon the 3-sphere, which are parametrized on the space of positive smooth functions f on the 2-sphere. All these metrics make the Hopf map a Riemannian submersion. The Hopf tube over an immersed curve γ in S2 is the complete lift π-1(γ) of γ, and we prove that any geodesic of this Hopf tube satisfies a Clairaut relation. A Hopf tube plays the role in S3 of the surfaces of revolution in R3. Furthermore, we show a geometric integration method of the Frenet equations for curves in those non-standard S3. Finally, if we consider the sphere S3 equipped with a family hf of Lorentzian metrics, then a new Clairautrelation is also obtained for timelike geodesics of the Lorentzian Hopf tube, and
a geometric integration method for curves is still possible. 相似文献
996.
In this paper we define the Kμ- transformation on certain spaces of generalized functions introduced by A.C. McBride by employing the kernel method. we also establish relations between the generalized Kμ- transformation and certain fractional integral operators. 相似文献
997.
The only known examples of Anosov diffeomorphisms are hyperbolic automorphisms of infranilmanifolds, and the existence of such automorphisms is a really strong condition on the rational nilpotent Lie algebra determined by the lattice, so called an Anosov Lie algebra. We prove that n⊕?⊕n (s times, s≥2) has an Anosov rational form for any graded real nilpotent Lie algebra n having a rational form. We also obtain some obstructions for the types of nilpotent Lie algebras allowed, and use the fact that the eigenvalues of the automorphism are algebraic integers (even units) to show that the types (5,3) and (3,3,2) are not possible for Anosov Lie algebras. 相似文献
998.
Jorge Cossio Sigifredo Herrón 《Journal of Mathematical Analysis and Applications》2008,345(1):583-592
We prove that an asymptotically linear Dirichlet problem which involves the p-Laplacian operator has multiple radial solutions when the nonlinearity has a positive zero and the range of the ‘p-derivative’ of the nonlinearity includes at least the first j radial eigenvalues of the p-Laplacian operator. The main tools that we use are a uniqueness result for the p-Laplacian operator and bifurcation theory. 相似文献
999.
1000.
Jorge Amaya 《Operations Research Letters》1985,4(1):31-34
The purpose of this paper is to unify the conditions under which curvilinear algorithms for unconstrained optimization converge. Particularly, two gradient path approximation algorithms and a trust region curvilinear algorithm are examined in this context. 相似文献